Launched as the British submarine H 6 on 12 May, 1915.
Commissioned at Quebec City, Canada on 10 June, 1915. The boat arrived at Plymouth, UK on 4 Aug 1915 after crossing the Atlantic under her own power.

Interned after running aground at
Schiermonnikoog in the Netherlands on 16 Jan, 1916. Purchased by the Dutch government
and commissoned as O 8.

Taken over by the German Navy on 14 May, 1940 at Den Helder, Netherlands. Commissioned
as UD-1 on 21 Nov, 1940. Taken out of service at Kiel, Germany on 23 Nov, 1943.
Scuttled at Kiel on 3 May, 1945. Wreck broken up.